The present invention relates to a photoelectric conversion device for use in solar cells, photodiodes, phototransistors, light sensors, solid-state cameras and so forth.
Owing to the increasing demand for energy and decreasing availability of nonrenewable energy sources such as fossil fuels, photovoltaic power has become increasingly attractive. There are marketed a variety of electric appliances powered by solar energy sources. The utilization of solar energy is promoted by economical manufacture and ease of processing.
An example of conventional solar cells is illustrated in FIG. 1. The solar cell comprises a Corning #7059 glass substrate 41, a SnO.sub.2 film patterned into a plurality of transparent electrodes 42-42"", an amorphous silicon semiconductor film including a PIN junction and patterned into a plurality of photosensitive layers 43-43"" covering the transparent electrodes, respectively, and an Al film patterned into a plurality of upper electrodes. By this configuration, connected in series are five individual electric conversion structures 411-411"", in which the edge portions 45, 45, 45", 45'" of Al electrodes 44, 44', 44", 44"" respectively, contact on transparent electrodes 42', 42", 42'", 42"", and e.g., the structure 411 comprises a transparent electrode 42, a photosensitive layer 44 and an Al electrode 44. The patterning of each film is performed by photolithography, laser patterning, masking methods and the like. The effective area of each conversion device is 1 cm.times.1 cm, for example. In accordance with our experiments, the open voltage, the fill factor and the short current of each structure of the illustrated solar cell were measured to be 2.7 V, 0.68 and 11 microamperes, respectively, when measured under illumination of 100 1.times. fluorescent light A. It is desirable if a further simplified process or structure is possible without degrading the performance thereof.